This invention relates to surgical irrigators and, more particularly, to electrically powered surgical irrigators of the type used in endoscopic procedures.
Today, numerous types of surgical irrigators are used for endoscopic surgery. One popular type of surgical irrigator, known as the Hydro-Surg Plus(trademark) irrigator, is illustrated and described in Delk et al. U.S. Pat. No. 5,807,313 which is hereby incorporated by reference into this specification.
The surgical irrigator illustrated in the ""313 patent is battery powered. It includes a small electrical motor which drives an impeller to force water under pressure from an irrigation bag to a handpiece enabling a surgeon to irrigate a surgical site through a wand or probe attached to the handpiece. In that particular case, the handpiece includes suction and irrigation lines which are controlled by trumpet valves. When the surgeon actuates the valve for the irrigation line, an electrical switch in the handpiece is closed which connects the motor to the batteries in the pumping unit, causing the pump to operate.
In the battery powered irrigators disclosed in the ""313 patent and in Saravia et al. U.S. Pat. No. 5,484,402 the pump, battery and motor are retained in a housing which is spiked directly into the irrigation bag. The pump outlet is connected by tubing to the handpiece. Typically, the tubing is about ten feet long which means that the wire which connects the on/off switch in the handpiece-to the batteries and motor in the housing is also ten feet long. Since there must be two wires, the total amount of additional wire required to position the switch in the handpiece is in the order of twenty feet. This length of copper wire results in a number of significant drawbacks as follows:
1. the wire itself is relatively expensive;
2. the weight of the copper wire adds to the weight of the tubing and, of course, the overall weight of the irrigator;
3. because the length of the wire is considerable, the added resistance diminishes the performance of the pump for a given battery source; and
4. the need to accommodate a switch in the handpiece detracts from the ergonomic design of the handpiece.
It is an object of this invention to provide an electrically powered surgical irrigator which avoids the above mentioned drawbacks of the prior art.
A more specific object of the invention is to provide a battery powered irrigator in which the switching mechanism for the pump motor is not connected to the motor by a substantial length of wire.
Furthermore, battery powered irrigators are not typically used in endoscopic procedures where body cavities are distended, i.e. arthroscopy and hysteroscopy. The reason is that it is necessary to maintain distension throughout the operation. This means that the pump must be on at all times and, very often, the battery life is not sufficient. It would be feasible, however, to use a battery powered irrigator for these procedures so long as the distension can be maintained when the pump is turned off from a lack of flow, for example if the outflow from the knee or the uterus is stopped.
Thus, it is a further object of the invention to provide a battery powered irrigator which can be used in endoscopic procedures such as arthroscopy and hysteroscopy, where body cavities are distended.
More particularly, it is an object of the invention to provide a battery powered irrigator in which the pump is actuated by liquid flow yet which is capable of maintaining pressure above atmospheric pressure when liquid flow is stopped.
Finally, in both of the above mentioned patents, the pumping unit includes a spike on its inlet port which is specially constructed so that when the pumping unit is attached to a conventional irrigation bag, the entire weight of the pumping unit is supported by the spike. Because the weight of the unit is considerable, the spike must include special support means such as a rib or it must be increased in diameter so as to create a friction fit which will support the unit. Regardless of which technique is used, the modified spike is relatively difficult to insert into a standard irrigation bag.
Accordingly, it is further object of the invention to provide a surgical irrigator in which a pump unit includes an inlet means with a spike which is easy to insert into a standard irrigation bag.
In accordance with a first feature of the invention, an electrically powered irrigation pump includes a pumping unit which is located in the vicinity of an irrigation bag and a handpiece connected by irrigation tubing to the pumping unit. A flow sensing device, connected at the output of the pumping unit, includes a float which moves when the surgeon opens the irrigation valve in the handpiece causing liquid to flow from the irrigation bag through the pumping unit. A photosensor detects movement of the float from its initial position. When it does so, it causes the circuit between the electrical source of power and the motor to close which then drives the impeller. When the irrigation valve in the handpiece is closed, the float returns to its initial position. This is detected by the photosensor which then causes the circuit between the power source and motor to open and the pump is turned off.
In the preferred embodiment, a one-way valve is placed in the input line between the irrigation bag and the pump. The one-way valve permits irrigant to flow into the pump but does not allow liquid to flow back into the irrigation bag when flow through the system stops, for example, by closure of the irrigation valve in the handpiece or by blockage of flow in an arthroscopic or hysteroscopic procedure. Thus cavity distension can be maintained in such procedures when flow is stopped.
In accordance with a further feature of the invention, the pumping unit includes clips which support the weight of the pumping unit on the IV pole or other device which holds the irrigation bag. The pumping unit includes a short flexible hose which is connected at one end to the inlet port of the pumping unit and at the other end to a conventional spike. The spike is coated with a lubricant such as silicone which makes it extremely easy for a nurse or other technician to attach the pumping unit to an irrigation bag.